A fine structure has fine protrusions formed on the surface thereof, and has a water repellent/hydrophilic function and an antireflection function depending on a material and a dimensional configuration of the fine structure. Therefore, surfaces of various substrates applied with such a fine structure can have an antireflection function with respect to light and a water repellent function to prevent adhesion of liquid, such as water in particular. For example, in order to provide such an antireflection function, a fine structure is favorably used for optical elements such as lenses for mechanical equipment (for example, refer to Patent Literature 1).